This invention relates generally to exercise apparatus for use by human beings for physiological conditioning and pertains more particularly to movable structures which provide a resistance force which is electrically controllable.
One prior art weight training apparatus is disclosed by Bradley in U.S. Pat. No. 4,138,106. Bradley discloses the use of an electrical rewind motor to control the restraining effect on a cable reel which is connected, through cables, to a lifting bar.
Another type of prior art exercise apparatus is disclosed by Jungreis in U.S. Pat. No. 3,731,922, entitled "Method of Isotonic Exercise". Jungreis discloses the use of an electric motor to slideably move a weight along a beam in order to vary the force on the muscles of the user.
Various combinations of mechanical elements have been used in the past to construct exercise devices. Levers, weights, tables, and pulleys are among the elements which have been combined in various ways to produce exercise apparatus. A problem with the prior art is the unavailability of low cost, lightweight, portable, adjustable exercise apparatus for which the magnitude of resistance force may be precisely controlled across a range of movement.